<template>
<div>
    <!--查询表单-->
<el-form :inline="true" class="demo-form-inline">

  <!-- 所属分类：级联下拉列表 -->
  <!-- 一级分类 -->
  <el-form-item label="课程类别">
    <el-select
      v-model="searchObj.subjectParentId"
      placeholder="请选择"
      @change="subjectLevelOneChanged">
      <el-option
        v-for="subject in subjectNestedList"
        :key="subject.id"
        :label="subject.title"
        :value="subject.id"/>
    </el-select>

    <!-- 二级分类 -->
    <el-select v-model="searchObj.subjectId" placeholder="请选择">
      <el-option
        v-for="subject in subSubjectList"
        :key="subject.id"
        :label="subject.title"
        :value="subject.id"/>
    </el-select>
  </el-form-item>

  <!-- 标题 -->
  <el-form-item>
    <el-input v-model="searchObj.title" placeholder="课程标题"/>
  </el-form-item>
  <!-- 讲师 -->
  <el-form-item>
    <el-select
      v-model="searchObj.teacherId"
      placeholder="请选择讲师">
      <el-option
        v-for="teacher in teacherList"
        :key="teacher.id"
        :label="teacher.name"
        :value="teacher.id"/>
    </el-select>
  </el-form-item>

  <el-button type="primary" icon="el-icon-search" @click="fetchData()">查询</el-button>
  <el-button type="default" @click="resetData()">清空</el-button>
</el-form>

<!-- 表格 -->
<el-table
  v-loading="listLoading"
  :data="list"
  element-loading-text="数据加载中"
  border
  fit
  highlight-current-row
  row-class-name="myClassList">

  <el-table-column
    label="序号"
    width="70"
    align="center">
    <template slot-scope="scope">
      {{ (page - 1) * limit + scope.$index + 1 }}
    </template>
  </el-table-column>

  <el-table-column label="课程信息" width="470" align="center">
    <template slot-scope="scope">
      <div class="info">
        <div class="pic">
          <img :src="scope.row.cover" :alt="scope.row.title" width="150px">
        </div>
        <div class="title">
          <a href="">{{ scope.row.title }}</a>
          <p>{{ scope.row.lessonNum }}课时</p>
        </div>
      </div>

    </template>
  </el-table-column>

  <el-table-column label="创建时间" align="center">
    <template slot-scope="scope">
      {{ scope.row.gmtCreate.substr(0, 10) }}
    </template>
  </el-table-column>
  <el-table-column label="发布时间" align="center">
    <template slot-scope="scope">
      {{ scope.row.gmtModified.substr(0, 10) }}
    </template>
  </el-table-column>
  <el-table-column label="价格" width="100" align="center" >
    <template slot-scope="scope">
      {{ Number(scope.row.price) === 0 ? '免费' : '¥' + scope.row.price.toFixed(2) }}
    </template>
  </el-table-column>
  <el-table-column prop="buyCount" label="付费学员" width="100" align="center" >
    <template slot-scope="scope">
      {{ scope.row.buyCount }}人
    </template>
  </el-table-column>

  <el-table-column label="操作" width="150" align="center">
    <template slot-scope="scope">
      <router-link :to="'/course/info/'+scope.row.id">
        <el-button type="text" size="mini" icon="el-icon-edit">编辑课程信息</el-button>
      </router-link>
      <router-link :to="'/course/chapter/'+scope.row.id">
        <el-button type="text" size="mini" icon="el-icon-edit">编辑课程大纲</el-button>
      </router-link>
      <el-button type="text" size="mini" icon="el-icon-delete" @click="removeDataById(scope.row.id)">删除</el-button>
    </template>
  </el-table-column>
</el-table>

<!-- 分页 -->
<el-pagination
  :current-page="page"
  :page-size="limit"
  :total="total"
  style="padding: 30px 0; text-align: center;"
  layout="total, prev, pager, next, jumper"
  @current-change="fetchData"
/>
</div>


</template>


<script>
import course from '@/api/course'
import teacher from '@/api/teacher'
import subject from '@/api/subject'

export default {

  data() {
    return {
      listLoading: true, // 是否显示loading信息
      list: null, // 数据列表
      total: 0, // 总记录数
      page: 1, // 页码
      limit: 10, // 每页记录数
      searchObj: {
        subjectParentId: '',
        subjectId: '',
        title: '',
        teacherId: ''
      }, // 查询条件
      teacherList: [], // 讲师列表
      subjectNestedList: [], // 一级分类列表
      subSubjectList: [] // 二级分类列表,
    }
  },

  created() { // 当页面加载时获取数据
    this.fetchData()
    // 初始化分类列表
    this.initSubjectList()
    // 获取讲师列表
    this.initTeacherList()
  },

  methods: {
    fetchData(page = 1) { // 调用api层获取数据库中的数据
      console.log('加载列表')
      // 当点击分页组件的切换按钮的时候，会传输一个当前页码的参数page
      // 解决分页无效问题
      this.page = page
      this.listLoading = true
      course.getPageList(this.page, this.limit, this.searchObj).then(response => {
        // debugger 设置断点调试
        console.log(response)
        if (response.code == 200) {
          this.list = response.data.records
          this.total = response.data.total
          console.log(this.total)
        }
        this.listLoading = false
      })
    },

    initTeacherList() {
      teacher.getList().then(response => {
        this.teacherList = response.data
      })
    },

    initSubjectList() {
      subject.getNestedTreeList().then(response => {
        this.subjectNestedList = response.data
      })
    },

    subjectLevelOneChanged(value) {
      for (let i = 0; i < this.subjectNestedList.length; i++) {
        if (this.subjectNestedList[i].id === value) {
          this.subSubjectList = this.subjectNestedList[i].children
          this.searchObj.subjectId = ''
        }
      }
    },

    resetData() {
      this.searchObj = {}
      this.subSubjectList = [] // 二级分类列表
      this.fetchData()
    },

    removeDataById(id) {
        // debugger
        this.$confirm('此操作将永久删除该课程，以及该课程下的章节和视频，是否继续?', '提示', {
            confirmButtonText: '确定',
            cancelButtonText: '取消',
            type: 'warning'
        }).then(() => {
            return course.removeById(id)
        }).then(() => {
            this.fetchData()
            this.$message({
                type: 'success',
                message: '删除成功!'
            })
        }).catch((response) => { // 失败
            if (response === 'cancel') {
                this.$message({
                    type: 'info',
                    message: '已取消删除'
                })
            }
        })
    }
  }
}
</script>

<style scoped>
.myClassList .info {
    width: 450px;
    overflow: hidden;
}
.myClassList .info .pic {
    width: 150px;
    height: 90px;
    overflow: hidden;
    float: left;
}
.myClassList .info .pic a {
    display: block;
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
}
.myClassList .info .pic img {
    display: block;
    width: 100%;
}
.myClassList td .info .title {
    width: 280px;
    float: right;
    height: 90px;
}
.myClassList td .info .title a {
    display: block;
    height: 48px;
    line-height: 24px;
    overflow: hidden;
    color: #00baf2;
    margin-bottom: 12px;
}
.myClassList td .info .title p {
    line-height: 20px;
    margin-top: 5px;
    color: #818181;
}
</style>